| Bucaramanga–Santa Marta Fault | |
|---|---|
| Bucaramanga–Santa Marta fault system (Sistema de) Falla(s) de Bucaramanga-Santa Marta | |
 View of the Bucaramanga Fault along Bucaramanga | |
  Location of the fault in Colombia Show map of Colombia Bucaramanga–Santa Marta Fault (Santander Department) Show map of Santander Department | |
 Topographic map of northern Colombia showing the fault | |
| Etymology | Bucaramanga,Santa Marta |
| Coordinates | 7°05′25″N73°05′15″W / 7.09028°N 73.08750°W /7.09028; -73.08750 |
| Country | Colombia |
| Region | Caribbean,Andean |
| State | Magdalena,Cesar,Norte de Santander,Santander |
| Cities | Santa Marta,El Paso,Bucaramanga,Floridablanca,Piedecuesta |
| Characteristics | |
| Elevation | 1–1,500 m (3.3–4,921.3 ft) |
| Range | Sierra Nevada de Santa Marta Eastern Ranges Andes |
| Part of | Andean faults |
| Segments | Santa Marta, Algarrobo, Bucaramanga Faults |
| Length | 674 km (419 mi) |
| Strike | 341 ± 23 (NNW-SSE) |
| Displacement | 110 km (68 mi) |
| Tectonics | |
| Plate | South American Plate |
| Status | Active |
| Earthquakes | Pre-Columbian era (~1020 AD) |
| Type | Strike-slip fault |
| Movement | Sinistral |
| Rock units | Caribbean,La Guajira,Tahamí &Chibcha terranes |
| Age | Neogene-Holocene |
| Orogeny | Andean |
TheBucaramanga–Santa Marta Fault (BSMF, BSF) orBucaramanga–Santa Marta fault system (Spanish:(Sistema de) Falla(s) de Bucaramanga-Santa Marta) is a major oblique transpressional sinistralstrike-slip fault (wrench fault) in thedepartments ofMagdalena,Cesar,Norte de Santander andSantander in northernColombia. The fault system is composed of two main outcropping segments, the Santa Marta and Bucaramanga faults, and an intermediate Algarrobo Fault segment in the subsurface. The system has a total length of 674 kilometres (419 mi) and runs along an average north-northwest to south-southeaststrike of 341 ± 23 from the Caribbean coast west ofSanta Marta to the northern area of theEastern Ranges of the ColombianAndes.
The fault system is a major bounding fault for varioussedimentary basins andigneous andmetamorphic complexes. The northern Santa Marta Fault segment separates theSinú-San Jacinto Basin andLower Magdalena Valley in the west from theSierra Nevada de Santa Marta to the east. The buried Algarrobo Fault segment forms the boundary between the Lower Magdalena Valley and northernMiddle Magdalena Valley to the west and theCesar-Ranchería Basin in the east. The Bucaramanga Fault segment separates the middle part of the Middle Magdalena Valley in the west from the Santander Massif in the east.
The fault system bounds and cuts the four largestterranes of theNorth Andes plate; theLa Guajira,Caribbean andTahamí terranes along the Santa Marta section and intraterrane movement in the AndeanChibcha terrane. Studies of the fault segments have shown the fault was active in thepre-Columbian era, around the year 1020, when the area around Bucaramanga was inhabited by theGuane. Various seismic events analysed to have occurred during theHolocene of the Bucaramanga Fault segment lead to the conclusion the fault is active.
The Bucaramanga–Santa Marta is a major fault system which extends for a total distance of 674 kilometres (419 mi) from the ColombianCaribbean coast to theEastern Ranges of the ColombianAndes to as far as about 6.5° N, south of the capital ofSantander,Bucaramanga. The fault system, with an averagestrike of 341 ± 23 degrees, is a major wrench fault with a sinistral (left-lateral) displacement ranging from 45 to 110 kilometres (28 to 68 mi) and a fault slip rate of 0.01 to 0.2 millimetres (0.00039 to 0.00787 in) per year.[1] The Santa Marta Fault forms the boundary between several distinct geological provinces: it is the western limit of theSanta Marta Massif with theSinú-San Jacinto Basin, farther to the south the fault separates theLower Magdalena Valley and northern Middle Magdalena Valley from theCesar-Ranchería Basin. The Santander Massif is separated from the central part of theMiddle Magdalena Valley along the southern Bucaramanga Fault segment of the fault system.[2]
The fault divides the northern part of the Eastern Ranges in two structurally distinct regions. TheAndean uplifted eastern block mainly comprises crystallineigneous andmetamorphic rocks ofPaleozoic andpre-Cambrian age, with lesser amounts ofJurassic,Triassic, andTertiary sedimentary rocks. In the western downthrown block, predominately sedimentary rocks of Quaternary and Tertiary age are found, with lesser amounts ofCretaceous and Jurassic rocks. The northern half of the fault is partially covered by Quaternary deposits in theCesar andMagdalena valleys.[2]
The fault is divided into three segments; the main Bucaramanga fault segment in the south, the Algarrobo Fault in the central section,[3] and the main Santa Marta fault segment in the northern part of the fault system.[4][5][6] Between the two main outcropping segments, the Algarrobo Fault is present in the subsurface, overlain by Quaternary sediments.[7][8][9][10][11] The urban centre of the majorcoal producing municipalityEl Paso, Cesar is located right above the fault.[9] The fault reappears at surface east ofTamalameque,Cesar, where it continues south-southeastward into the Eastern Ranges in the departments of Norte de Santander and Santander.[12][13][14][15][16][17] The fault can be traced untilSan Andrés,Santander.[18] The Bucaramanga Fault possibly continues as the compressionalBoyacá andSoapaga Faults on theAltiplano Cundiboyacense.[19]
| Municipality bold is capital | Department | Altitude of urban centre | Inhabitants 2015 | Notes |
|---|---|---|---|---|
| Santa Marta | Magdalena | 0 m (0 ft) | 466,000 | |
| Ciénaga | Magdalena | 10 m (33 ft) | 104,897 | |
| Zona Bananera | Magdalena | 30 m (98 ft) | 60,524 | |
| Aracataca | Magdalena | 40 m (130 ft) | 39,473 | |
| Fundación | Magdalena | 10 m (33 ft) | 57,344 | |
| Algarrobo | Magdalena | 24 m (79 ft) | 12,576 | |
| El Copey | Cesar | 180 m (590 ft) | 27,212 | |
| Bosconia | Cesar | 200 m (660 ft) | 37,248 | |
| El Paso | Cesar | 36 m (118 ft) | 22,832 | |
| Chiriguaná | Cesar | 40 m (130 ft) | 19,650 | |
| Curumaní | Cesar | 112 m (367 ft) | 24,367 | |
| Chimichagua | Cesar | 49 m (161 ft) | 30,658 | |
| Pailitas | Cesar | 77 m (253 ft) | 17,166 | |
| Pelaya | Cesar | 50 m (160 ft) | 17,910 | |
| La Gloria | Cesar | 50 m (160 ft) | 12,938 | |
| El Carmen | Norte de Santander | 761 m (2,497 ft) | 14,005 | |
| Teorama | Norte de Santander | 72 m (236 ft) | 21,524 | |
| González | Cesar | 1,240 m (4,070 ft) | 6990 | |
| Ocaña | Norte de Santander | 1,202 m (3,944 ft) | 98,992 | |
| San Martín | Cesar | 119 m (390 ft) | 18,548 | |
| San Alberto | Cesar | 125 m (410 ft) | 24,653 | |
| Ábrego | Norte de Santander | 1,398 m (4,587 ft) | 38,627 | |
| La Esperanza | Norte de Santander | 1,566 m (5,138 ft) | 12,012 | |
| Cáchira | Norte de Santander | 2,025 m (6,644 ft) | 10,970 | |
| El Playón | Santander | 469 m (1,539 ft) | 11,776 | |
| Rionegro | Santander | 590 m (1,940 ft) | 27,114 | |
| Bucaramanga | Santander | 959 m (3,146 ft) | 528,575 | |
| Floridablanca | Santander | 925 m (3,035 ft) | 266,669 | |
| Piedecuesta | Santander | 1,005 m (3,297 ft) | 156,167 | |
| Cepitá | Santander | 660 m (2,170 ft) | 1865 | |
| San Andrés | Santander | 1,777 m (5,830 ft) | 8540 |
The Bucaramanga-Santa Marta Fault system is located in northwestern South America, on theNorth Andes Plate, where the 20 ± 2 millimetres (0.787 ± 0.079 in)/yr east to southeastward movingCaribbean,[52] 60 mm (2.4 in)/yr eastwardsubductingMalpelo,[53] andSouth American Plates converge. Since Early Mesozoic times, the western portion of Colombia was subjected to different episodes of subduction, accretion and collision, at the boundaries of the South America continental and the oceanicFarallon, Nazca, and Caribbean Plates and various island arcs.[54] The interaction of the plate tectonic movements formed the Northern Andean Block, separated from the Maracaibo Block by the Bucaramanga-Santa Marta Fault.[55] The Northern Andean Block is subdivided into tectonic realms, with the Bucaramanga-Santa Marta Fault separating the Central Continental Sub-plate Realm in the west from the Maracaibo Sub-plate Realm in the east.[56] It has been suggested that these two realms are dominated by respectively Nazca and Caribbean Plate subduction.[57] The compressional stress regime caused the formation of the oblique sinistral Bucaramanga-Santa Marta Fault and dextralOca andBoconó Faults.[58]
The interplay between the Santa Marta andOca Faults produced offshore Caribbean platforms and valleys north of theSierra Nevada de Santa Marta nearTaganga.[59] Uplift along the western margin of the Santa Marta Fault probably commenced in thePliocene.[60]
The Bucaramanga Fault intersects with theBoconó Fault at the Santander Massif.[61] In this area, the top of the subducting slab has been estimated at an initial depth of approximately 100 kilometres (62 mi), then a horizontal part for about 50 kilometres (31 mi), and a farther descending section to reach a depth of around 200 kilometres (120 mi). The slab section, called Bucaramanga slab, here has a dip that continues to theoceanic crust of the Caribbean seafloor. Towards the north of theBucaramanga Nest or Swarm, in a north–south area approximately 200 kilometres (120 mi) in length, a well-definedWadati-Benioff Zone extending to 175 kilometres (109 mi) depth has been identified.[62]
A study published in 2009 about the Bucaramanga segment of the fault system revealed that the fault had eight episodes of activity during the lateHolocene.[63] The most recent activity has been inferred to have been around the year 1020.[64] During thispre-Columbian era, the area around Bucaramanga was inhabited by theindigenousGuane. The authors consider the Bucaramanga Fault therefore as active.[63]
Other faults in the seismically active zone, namedBucaramanga Nest, produced 27 earthquakes of magnitudes 4.0 to 5.3 between May 2012 and January 2013.[65]
{{citation}}: CS1 maint: multiple names: authors list (link){{citation}}: CS1 maint: multiple names: authors list (link){{citation}}: CS1 maint: multiple names: authors list (link){{citation}}: CS1 maint: multiple names: authors list (link)| Tectonic plates |   | ||||||||||
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| Sources | Paris, Gabriel; Machette, Michael N.; Dart, Richard L.; Haller, Kathleen M. (2000).Map and Database of Quaternary Faults and Folds in Colombia and its Offshore Regions(PDF).USGS. pp. 1–66. Retrieved2017-06-20. Gómez Tapias, Jorge; Montes Ramírez, Nohora E.; Almanza Meléndez, María F.; Alcárcel Gutiérrez, Fernando A.; Madrid Montoya, César A.; Diederix, Hans (2015).Geological Map of Colombia.Servicio Geológico Colombiano. pp. 1–212. Retrieved2019-10-29. Various authors (2014).Enciclopedia de desastres naturales históricos de Colombia(PDF).Universidad del Quindío. pp. 1–21. Retrieved2017-06-20. | ||||||||||
